javascript缩短今天的时间为时分秒格式

//今天零点
function getTordayZero(){
    return new Date(new Date().toLocaleDateString())
}
//缩短时间
function shortTime(t){
    var time=new Date(t);
    var torday=getTordayZero();
    if(torday<time){
        var hours = time.getHours(); //获取当前小时
        if(hours<10){
            hours="0"+hours;
        }
        var minutes = time.getMinutes(); //获取当前分钟
        if(minutes<10){
            minutes="0"+minutes;
        }
        var seconds = time.getSeconds(); //获取当前秒
        if(seconds<10){
            seconds="0"+seconds;
        }
        return hours+":"+minutes+":"+seconds;
    }
    return t;
}